An experimental study on drilling of titanium alloy using CO2 laser

Abstract

Laser drilling is a popular method as it eliminates the problem of chatter and vibration due to the absence of physical contact between the tool and workpiece. Tool breakage, a common phenomenon that occurs due to bending of the tool in making of slender holes using conventional drilling, can also be avoided. However, quality of the hole measured in terms of circularity, taper and spatter area is the major concern during laser drilling. The present investigation attempts to find out the optimum parametric setting during drilling of Ti6Al4V using CO 2 laser in order to achieve quality holes. Experiments have been conducted to assess the influence of machining parameters, viz. flushing pressure, laser power and pulse frequency, on the performance characteristics such as taper of kerf, heat-affected zone (HAZ) and spatter area. Taguchi's L 9 orthogonal array has been used to design the experimental layout as it reduces the experimental cost and time. Analysis of variance has been performed to assess the effect of machining parameter on the performance characteristics. It has been observed that laser power has significant influence on taper of kerf, HAZ and spatter area. Based on desirability approach, the study suggests that all the performance characteristics can be simultaneously optimized at flushing pressure of 40 Pa, laser power of 2250 W and pulse frequency of 1600 Hz. The study also presents a numerical model to simulate the laser drilling process. Since comparison of experimental and numerical model shows a relative error within 10%, adequacy of the numerical model for assessment of quality characteristics of laser drilled holes is justified.

Drilling of micro-holes on titanium alloy using pulsed Nd:YAG laser: Parametric appraisal and prediction of performance characteristics

“…Circularity of hole for entry and exit is expressed in equation (5). 20 If CIR value is equal to 1, then it implies that the hole is a perfect circle…”

“…15–17 The standard lasers used for the laser machining process are ruby, Nd:YAG (Neodymium Yttrium Aluminium Garnet) and carbon dioxide (CO 2 ) gas laser. 18–20 Lasers find wide spread application in various fields such as electrical, electronics, micro-electro-mechanical systems (MEMS), medical science, metal forming, aviation and automobile sectors. 21–23 Also, lasers are widely used for various material processing techniques, namely, forming, bending, sintering, cutting, welding, drilling and additive manufacturing.…”

“…In laser drilling process, a high-energy infrared laser beam is focused on a spot of the workpiece (generally varies between 0.1 and 2.0 mm in diameter) and causes melting, vaporization and chemical degradation throughout the depth of the material. 13,14,20 An assistant gas is used to flush the molten material from the surrounding near the drilled hole. Ng and Li 28 have investigated the effect of laser process parameters such as pulse width and laser peak power on material ejection and quality of hole in terms of circularity during in laser percussion drilling.…”

Energy Efficiency in CO2 Laser Processing of Hardox 400 Material

“…In the past few years, researchers studied the possibility of cutting with a CO 2 laser of different materials such as methyl polymethacrylate [16], Al 6061-T6 alloy [17], 304 stainless steel [18], AISI 1045 austenitic steel [19], AlSI 304, AlMg3 and St37-2 [20], SS41 and SUS304 [21], pure titanium and Ti-6Al-4V titanium alloys [22], Ti6Al4V alloy [23] and Nickel-based super alloys Nimonic 263 [24].…”

“…A similar conclusion was reached by Chatterjee et al when studying laser drilling of Ti6Al4V alloy sheets. In order to generate holes with quality surface and good taper, the laser power must be set correctly, as it is the parameter with the greatest influence [23]. Kang et al used ultrafast lasers in the production of WC-Co alloy steel cutting tools.…”